Patent GB-190224946-A (GB)
Title: Improvements in or relating to Fluid Pressure Brake Apparatus for Railway and like Vehicles.
Inventor: CLOUD JOHN WILLS
IPC: B60T15/54
Filed: 1902-11-13
Granted: 1903-09-10
Abstract: 24,946. Cloud, J. W. Nov. 13. Brakes.-Relates to automatic air-pressure brakes of the Westinghouse type, and consists of an automatic valve which will permit the gradual or partial release of the brakes. The valve is connected to the release port of the triple valve, and is adapted to control the exhaust from the brake cylinder in a manner dependent upon the pressure in the main pipe. The valve is controlled by air admitted to a small reservoir 1 from the train pipe. The valve itself 23 is placed in a small chamber 3, between which and the reservoir 1 is formed another chamber 2. Flexible diaphragms 4, 5 between the chambers 1, 2 and 2, 3 are connected to the valve 23. The chamber 2 is connected to the main pipe at 31. Air can pass from the chamber 2 to the chamber 1 through a non-return valve 33, and can return through a spring-loaded valve 34 which keeps only a limited excess of pressure in the reservoir 1 above that in the main pipe when the pressure in the main pipe is reduced. The chamber 3 is connected by a pipe at 24 to the release port of the triple valve. When the valve 23 is open, the exhaust from the brake cylinder, after passing the triple valve, enters the chamber 3 and passes through the valve 23 and passages 17, 18, 19 to the atmosphere. When the brakes are fully released, the pressures in the chambers 1, 2 are both equal to that in the main pipe, and a spring 29 acting against the diaphragm 5 keeps the valve 23 open. The spring is adjusted by means of a nut 26 screwed on the valve tube 25, the tube being rotated by means of a locked nut 16, and the nut held from rotating by a feather 28. On applying the brakes by lowering the pressure in the main pipe, the air in the chamber 1 acting on the diaphragm 4 closes the valve 23. On slightly raising the pressure in the main pipe, the brake cylinder is caused to exhaust through the triple valve to the chamber 3. The pressure of the exhaust in the chamber 3 together with the increased pressure in the chamber 2 causes the opening of the valve 23, and the exhaust can then pass to the atmosphere until the valve 23 closes again owing to the decrease of pressure in the brake cylinder and consequently in the chamber 3. The brakes are thus left partly on. On again raising the pressure in the main pipe, the action is repeated, and so on until, the full pressure being admitted into the train pipe, the valve 23 is held open and the brakes fully released. The brakes may be fully released in the first instance by admitting the full pressure to the main pipe and therefore to the chamber 2. In a modification, the chamber 1 is made smaller, and is connected to an auxiliary reservoir, the valve 23 is made separate from the spindle of the diaphragms and is opened by a spring, and the spring 29 is replaced by another diaphragm on the other end of the spindle and having one side exposed to the chamber 1 and the other to the atmosphere. In another modification, the valve and its seat are fitted inside the diaphragm spindle, and the valve is opened by coming against a fixed stop. The two valves 33, 34 may be replaced by a slide valve operated by a piston or diaphragm and a spring.